Osteoarthritis (OA) is the most common rheumatic disease of the elderly, with 40 million Americans estimated to have radiological evidence of OA. As part of the ongoing studies of OA in the Baltimore Longitudinal Study of Aging (BLSA) we have presented data on radiographic hand OA in men, and have evaluated the possible association of metabolic and physiologic factors with hand OA. We have now evaluated the prevalence of definite radiographic hand OA in 422 women of the BLSA, and have demonstrated that there is a marked increase in abnormal radiographs with age. Women under 40 years of age had < 1% abnormal readings which increased starting in the 40's with 25% abnormal, continuing in the 50's (77%) and 60's (94%) with > 99% of the women over 70 having abnormal radiographs. In 325 women over the age of 40 estimates of fat mass and distribution were positively related to OA grade, while estimates of bone mass of the hand and arm were negatively related to OA grade. These associations were not present when the age distribution of the higher OA grades was accounted for. Similarly, serum levels of Insulin-like growth factor-I were inversely related to OA grade in 115 women aged 22-86, but this association also was not present when age was taken into account. These studies fail to support the hypothesis that physiologic and metabolic factors are associated with hand OA in women, independent of their known association with age.